Anti-halation layers for photographic material



Sept. 27, 1932. w. SCHNEIDER Y 1,379,537

I ANTIHALATION LAYERS FOR PHOTOGRAPHIC MATERIAL H Filed 001;. 15. 1950 Ifi, Sens/f/ked fmu/s/an avp/ ' IIIIIIIIIIIIIIIIIIIII/I/I/II IIII/I/IIIIII/Il/II II :1

4/7///7a/9//o0 layer Base In venfor:

Patented Sept. 2'7, 1932 UNITED STATES PATENT OFFICE WILHELM SCHNEIDER,F DESSAU IN ANHALT, GERMANY, ASSIGNOR TO AGFA ANSGO CORPORATION, OFBINGHAMTON, NEW YORK, A CORPORATION OF NEW YORK AN TI-I-TALATION LAYERSFOR PHOTOGRAPHIO MATERIAL Application filed October 15, 1930, Serial No.

My present invention relates to photographic materials and moreparticularlyto new anti-halation layers as used on photogra hic platesor films.

he use of dyes of the fuchsone group, for instance, aurine, for themanufacture of anti-halation layers i known. These dyes have, however,the inconvenience that they are soluble only in strongly alkalinedevelopers, whilst they are insoluble in developers of a lessalkalinity, for instance, in developers containing borax. 'Furthermore,the developer is intensely colored by the aurine which dissolves forminga phenolate.

According to the present invention, antihalation layers of an increasedsolubility in alkali are made by using as dyes bodies of the fuchsoneseries which contain one or more carboxyl-groups in the molecule. Thesedyes a very quickly and completely dissolve, even in very weaklyalkaline developers, and furthermore, have the advantage of coloring thedeveloper considerably less, because, owing to the presence of'thecarboxyl-groups a formation of phenolate in the developer is practicallyimpossible. The new anti-halation layers are made in known manner; thedyes are either dispersed in a suitable binding agent, for instancegelatin, gum arabic, glucose or the like or, applied in an alcoholicsolution without using a binding agent. Besides the fuchsone dyesmentioned above the layers guy, of course, also contain other suitableyes.

In the accompanying drawing Fig. 1 and Fig. 2 illustrate my invention,the view being a conventional, exa gerated, cross-sectional showing.Fig. 1 s ows the anti-halation layer applied to the back of the film orplate and Fig. 2 the antihalation layer arranged between the sensitizedemulsion and the base of the photographic film or plate.

The following examples illustrate the invention:--

Example 1.7 grams of gelatin are dis- 48B,990, and in Germany October30, 1929.

solved in 1000 cc. of water and grains of aurine-di-carboxylic acidcorresponding probably to the formula coon 50 CeHa COOH C$H(=O I aredissolved in 100 cc. of alcohol while add- 5 \O H \sH4=O are dissolvedin 900 'cc. of alcohol and the solution is mixed with one prepared bydissolving 15 grams of shellac in 100 cc. of alcohol. The mixture isused for the manufacture of anti-halation layers on the back of platesor films.

Ewample 31-50 to 100 carboxy-fuchsone of the grams of hydroxy formulafacture of anti-halation layers on the back plates or films.

My present invention is not limited to the foregoing examples or to thespecific details given therein. Thus, I may use, for instance, otherdyes of the fuchsone series substituted in the manner described, such asaurine-tricarboxylic acid and those substituted in the nuclei byhalogen, alkyl and equivalent substituents. Or I may use other bindingagents well known in the art containing the dye either in solution or ina fine dispersion; finally as mentioned above the use of a binding'agent may be dispensed with, and the dye may be applied immediately uponthe suport. p What I claim is 1. Photographic materials provided with ananti-halation layer containing a dye of the fuchsone series having atleast one carboxylic group in the molecule.

2. Photographic materials provided with an antihalation layer containingaurine-dicarboxylic acid.

3. Photographic material provided with an antihalation layer containingaurinemono-carboxylic acid.

4. Photographic material provided with an antihalation layer containinghydroxycarbox'y-fuchsone.

In testimony whereof, I affix my signature.

- WILHELM SCHNEIDER.

